# Proof of Existence with Broadcast **URL:** \ **Category:** Contracts\ **Created:** [September 25, 2014, 9:53am UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451 "2014-09-25T09:53:16Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![JPJA](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/jpja/32/1324_2.png) [@JPJA](https://forums.counterparty.io/u/JPJA)\ **Post date:** [September 25, 2014, 9:53am UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/1 "2014-09-25T09:53:16Z")
Proof-of-existence on the blockchain is an excellent way of proving that a file existed on a specific time. Read about it here [http://www.proofofexistence.com/about](http://www.proofofexistence.com/about) You can use their service or you can upload the hash with a broadcast through Counterwallet. In my case I used it to prove that a financial report existed today. For future proof I just need to keep the exact same file. Its hash is forever stored on time-stamped on the blockchain. ---
**Author:** ![Equality\_7\_2521](https://avatars.discourse-cdn.com/v4/letter/e/a587f6/32.png) [@Equality\_7\_2521](https://forums.counterparty.io/u/Equality_7_2521)\ **Post date:** [October 15, 2014, 12:11pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/2 "2014-10-15T12:11:46Z")
Great idea. It would be really nice to have this feature in Counterwallet. You have to pay to embed the digest/hash anyway. Then Blockscan or another webpage could be used to host and verify documents at a later date. ---
**Author:** ![Equality\_7\_2521](https://avatars.discourse-cdn.com/v4/letter/e/a587f6/32.png) [@Equality\_7\_2521](https://forums.counterparty.io/u/Equality_7_2521)\ **Post date:** [October 15, 2014, 2:11pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/3 "2014-10-15T14:11:51Z")
Also, another neat feature in Counterwallet would be to write arbitrary messages that would then be Broadcast. Or a plugin to allow such features. For some reason I really want an “I was here” button that I can press and let humanity/posterity know that I was indeed here. ---
**Author:** ![mtbitcoin](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/mtbitcoin/32/389_2.png) [@mtbitcoin](https://forums.counterparty.io/u/mtbitcoin)\ **Post date:** [October 15, 2014, 5:25pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/4 "2014-10-15T17:25:53Z")
This could actually be built into the protocol. Viacoin (which is a fork on Counterparty) just introduced their document notary built on clearinghouse. Embedding message via the broadcast for notary is possible and is something I have considered, but this is not the most efficient way to do it.. ---
**Author:** ![mtbitcoin](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/mtbitcoin/32/389_2.png) [@mtbitcoin](https://forums.counterparty.io/u/mtbitcoin)\ **Post date:** [October 15, 2014, 7:07pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/5 "2014-10-15T19:07:24Z")
[http://blog.viacoin.org/2014/10/14/blockchain-notary.html](http://blog.viacoin.org/2014/10/14/blockchain-notary.html) ---
**Author:** ![weex](https://avatars.discourse-cdn.com/v4/letter/w/41988e/32.png) [@weex](https://forums.counterparty.io/u/weex)\ **Post date:** [October 15, 2014, 7:57pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/6 "2014-10-15T19:57:24Z")
An important part of this is the interface that lets the user load the document and verify that the hash was embedded in the block chain. Either Blockchain.info or [blockscan.com](http://blockscan.com) could implement at least the verification and search features while Counterwallet could do the proving. It would be interesting to know any patterns [POE.com](http://POE.com) sees but I’d imagine a document would be verified a few to hundreds of times vs. being proved just a handful of times on changes. All in all, I don’t really see the benefit of conflating Counterparty with proof-of-existence. Being able to prove to a third party that you’re in control of an address and by extension any tokens in it would be more focused and useful in the Counterparty context. This reminds me about the idea that delegation might be nice. What if I signed a statement that an account at [blockscan.com](http://blockscan.com) is allowed to sign statements of ownership for me?  Kind of like an oauth for address ownership. ---
**Author:** ![mtbitcoin](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/mtbitcoin/32/389_2.png) [@mtbitcoin](https://forums.counterparty.io/u/mtbitcoin)\ **Post date:** [October 16, 2014, 4:22am UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/7 "2014-10-16T04:22:40Z")
We could do that with a signed account at blockscan but this would mean a centralized time stamping authority... And in reality I am not sure how useful would such a service be for Counterparty ?? ---
**Author:** ![JPJA](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/jpja/32/1324_2.png) [@JPJA](https://forums.counterparty.io/u/JPJA)\ **Post date:** [October 16, 2014, 10:20am UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/8 "2014-10-16T10:20:54Z")
Broadcast, as it is implemented now, is perfect for my use.  What makes it great is that all messages from one address can be viewed on Blockscan (and potentially any other third party site). Proof of existence is just one niche use of broadcasting. I wrote a blog post about how analysts can use it to prove their track-record: [http://jpja.net/2014/10/proof-of-prediction/](http://jpja.net/2014/10/proof-of-prediction/) ---
**Author:** ![Equality\_7\_2521](https://avatars.discourse-cdn.com/v4/letter/e/a587f6/32.png) [@Equality\_7\_2521](https://forums.counterparty.io/u/Equality_7_2521)\ **Post date:** [October 16, 2014, 10:46am UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/9 "2014-10-16T10:46:05Z")
> Broadcast, as it is implemented now, is perfect for my use.  > What makes it great is that all messages from one address can be viewed on Blockscan (and potentially any other third party site). > > > > Proof of existence is just one niche use of broadcasting. I wrote a blog post about how analysts can use it to prove their track-record: [http://jpja.net/2014/10/proof-of-prediction/](http://jpja.net/2014/10/proof-of-prediction/) Proof of Prediction is useful for “Futurists” too. [http://mashable.com/2014/03/19/false-future-predictions/](http://mashable.com/2014/03/19/false-future-predictions/) ---
**Author:** ![deliciousowl](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/deliciousowl/32/31_2.png) [@deliciousowl](https://forums.counterparty.io/u/deliciousowl)\ **Post date:** [October 22, 2014, 2:24pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/10 "2014-10-22T14:24:41Z")
> We could do that with a signed account at blockscan but this would mean a centralized time stamping authority... > > And in reality I am not sure how useful would such a service be for Counterparty ?? It’s already possible to post a hash of a file as a broadcast, and to verify it on Blockscan or the API. > Also, another neat feature in Counterwallet would be to write arbitrary messages that would then be Broadcast. Or a plugin to allow such features. For some reason I really want an “I was here” button that I can press and let humanity/posterity know that I was indeed here. I’m really confused by your request. This is already possible. And in counterpartyd the text can be like 1K+ in size, which will be added to Counterwallet soon. ---
**Author:** ![Equality\_7\_2521](https://avatars.discourse-cdn.com/v4/letter/e/a587f6/32.png) [@Equality\_7\_2521](https://forums.counterparty.io/u/Equality_7_2521)\ **Post date:** [October 23, 2014, 4:45pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/11 "2014-10-23T16:45:36Z")
> > We could do that with a signed account at blockscan but this would mean a centralized time stamping authority… > > > > And in reality I am not sure how useful would such a service be for Counterparty ?? > > It’s already possible to post a hash of a file as a broadcast, and to verify it on Blockscan or the API. > > > Also, another neat feature in Counterwallet would be to write arbitrary messages that would then be Broadcast. Or a plugin to allow such features. For some reason I really want an “I was here” button that I can press and let humanity/posterity know that I was indeed here. > > I’m really confused by your request. This is already possible. And in counterpartyd the text can be like 1K+ in size, which will be added to Counterwallet soon. I don’t see an option in Counterwallet to Broadcast arbitrary messages yet? (Oh, I see you addressed that). All I was talking about was having plugins for Counterwallet that might allow for additional functionality - like Proof-of-Existence style functionality or buttons to embed comments like “I was here” or “I love X” in the Bitcoin Blockchain. ---
**Author:** ![deliciousowl](https://yyz2.discourse-cdn.com/flex004/user_avatar/forums.counterparty.io/deliciousowl/32/31_2.png) [@deliciousowl](https://forums.counterparty.io/u/deliciousowl)\ **Post date:** [October 23, 2014, 5:32pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/12 "2014-10-23T17:32:48Z")
Address action -\> Broadcast. you can put an arbitrary text in there ---
**Author:** ![Equality\_7\_2521](https://avatars.discourse-cdn.com/v4/letter/e/a587f6/32.png) [@Equality\_7\_2521](https://forums.counterparty.io/u/Equality_7_2521)\ **Post date:** [October 23, 2014, 6:47pm UTC](https://forums.counterparty.io/t/proof-of-existence-with-broadcast/451/13 "2014-10-23T18:47:38Z")
> Address action → Broadcast. you can put an arbitrary text in there Woah, it’s amazing the features you’d miss sometimes. Thanks!